1161 lines
42 KiB
Text
1161 lines
42 KiB
Text
@c -*- Texinfo -*-
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@c Copyright (c) 1990 1991 1992 1993 Free Software Foundation, Inc.
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@c This file is part of the source for the GDB manual.
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@c This text diverted to "Remote Debugging" section in general case;
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@c however, if we're doing a manual specifically for one of these, it
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@c belongs up front (in "Getting In and Out" chapter).
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@ifset REMOTESTUB
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@node Remote Serial
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@subsection The @value{GDBN} remote serial protocol
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@cindex remote serial debugging, overview
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To debug a program running on another machine (the debugging
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@dfn{target} machine), you must first arrange for all the usual
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prerequisites for the program to run by itself. For example, for a C
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program, you need
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@enumerate
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@item
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A startup routine to set up the C runtime environment; these usually
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have a name like @file{crt0}. The startup routine may be supplied by
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your hardware supplier, or you may have to write your own.
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@item
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You probably need a C subroutine library to support your program's
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subroutine calls, notably managing input and output.
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@item
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A way of getting your program to the other machine---for example, a
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download program. These are often supplied by the hardware
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manufacturer, but you may have to write your own from hardware
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documentation.
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@end enumerate
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The next step is to arrange for your program to use a serial port to
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communicate with the machine where @value{GDBN} is running (the @dfn{host}
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machine). In general terms, the scheme looks like this:
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@table @emph
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@item On the host,
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@value{GDBN} already understands how to use this protocol; when everything
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else is set up, you can simply use the @samp{target remote} command
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(@pxref{Targets,,Specifying a Debugging Target}).
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@item On the target,
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you must link with your program a few special-purpose subroutines that
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implement the @value{GDBN} remote serial protocol. The file containing these
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subroutines is called a @dfn{debugging stub}.
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@end table
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The debugging stub is specific to the architecture of the remote
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machine; for example, use @file{sparc-stub.c} to debug programs on
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@sc{sparc} boards.
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@cindex remote serial stub list
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These working remote stubs are distributed with @value{GDBN}:
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@table @code
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@item sparc-stub.c
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@kindex sparc-stub.c
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For @sc{sparc} architectures.
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@item m68k-stub.c
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@kindex m68k-stub.c
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@kindex Motorola 680x0
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@kindex 680x0
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For Motorola 680x0 architectures.
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@item i386-stub.c
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@kindex i386-stub.c
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@kindex Intel
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@kindex 386
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For Intel 386 and compatible architectures.
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@end table
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The @file{README} file in the @value{GDBN} distribution may list other
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recently added stubs.
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@menu
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* Stub Contents:: What the stub can do for you
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* Bootstrapping:: What you must do for the stub
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* Debug Session:: Putting it all together
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* Protocol:: Outline of the communication protocol
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@end menu
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@node Stub Contents
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@subsubsection What the stub can do for you
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@cindex remote serial stub
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The debugging stub for your architecture supplies these three
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subroutines:
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@table @code
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@item set_debug_traps
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@kindex set_debug_traps
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@cindex remote serial stub, initialization
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This routine arranges for @code{handle_exception} to run when your
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program stops. You must call this subroutine explicitly near the
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beginning of your program.
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@item handle_exception
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@kindex handle_exception
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@cindex remote serial stub, main routine
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This is the central workhorse, but your program never calls it
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explicitly---the setup code arranges for @code{handle_exception} to
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run when a trap is triggered.
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@code{handle_exception} takes control when your program stops during
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execution (for example, on a breakpoint), and mediates communications
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with @value{GDBN} on the host machine. This is where the communications
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protocol is implemented; @code{handle_exception} acts as the @value{GDBN}
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representative on the target machine; it begins by sending summary
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information on the state of your program, then continues to execute,
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retrieving and transmitting any information @value{GDBN} needs, until you
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execute a @value{GDBN} command that makes your program resume; at that point,
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@code{handle_exception} returns control to your own code on the target
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machine.
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@item breakpoint
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@cindex @code{breakpoint} subroutine, remote
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Use this auxiliary subroutine to make your program contain a
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breakpoint. Depending on the particular situation, this may be the only
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way for @value{GDBN} to get control. For instance, if your target
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machine has some sort of interrupt button, you won't need to call this;
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pressing the interrupt button will transfer control to
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@code{handle_exception}---in effect, to @value{GDBN}. On some machines,
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simply receiving characters on the serial port may also trigger a trap;
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again, in that situation, you don't need to call @code{breakpoint} from
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your own program---simply running @samp{target remote} from the host
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@value{GDBN} session will get control.
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Call @code{breakpoint} if none of these is true, or if you simply want
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to make certain your program stops at a predetermined point for the
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start of your debugging session.
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@end table
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@node Bootstrapping
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@subsubsection What you must do for the stub
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@cindex remote stub, support routines
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The debugging stubs that come with @value{GDBN} are set up for a particular
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chip architecture, but they have no information about the rest of your
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debugging target machine. To allow the stub to work, you must supply
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these special low-level subroutines:
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@table @code
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@item int getDebugChar()
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@kindex getDebugChar
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Write this subroutine to read a single character from the serial port.
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It may be identical to @code{getchar} for your target system; a
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different name is used to allow you to distinguish the two if you wish.
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@item void putDebugChar(int)
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@kindex putDebugChar
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Write this subroutine to write a single character to the serial port.
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It may be identical to @code{putchar} for your target system; a
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different name is used to allow you to distinguish the two if you wish.
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@item void exceptionHandler (int @var{exception_number}, void *@var{exception_address})
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Write this function to install @var{exception_address} in the exception
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handling tables. You need to do this because the stub does not have any
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way of knowing what the exception handling tables on your target system
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are like (for example, the processor's table might be in @sc{rom},
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containing entries which point to a table in @sc{ram}).
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@var{exception_number} is the exception number which should be changed;
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its meaning is architecture-dependent (for example, different numbers
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might represent divide by zero, misaligned access, etc). When this
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exception occurs, control should be transferred directly to
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@var{exception_address}, and the processor state (stack, registers,
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etc.) should be just as it is when a processor exception occurs. So if
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you want to use a jump instruction to reach @var{exception_address}, it
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should be a simple jump, not a jump to subroutine.
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@c For the 386, doesn't the interrupt gate contain a privilege level?
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@c If so, what should it be set to? I suspect the answer is the
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@c privilege level in effect at the time that exceptionHandler is
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@c called, but I'm not sure. FIXME.
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For the 386, @var{exception_address} should be installed as an interrupt
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gate so that interrupts are masked while the handler runs. The
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@sc{sparc} and 68k stubs are able to mask interrupts themself without
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help from @code{exceptionHandler}.
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@item void flush_i_cache()
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@kindex flush_i_cache
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Write this subroutine to flush the instruction cache, if any, on your
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target machine. If there is no instruction cache, this subroutine may
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be a no-op.
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On target machines that have instruction caches, @value{GDBN} requires this
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function to make certain that the state of your program is stable.
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@end table
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@noindent
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You must also make sure this library routine is available:
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@table @code
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@item void *memset(void *, int, int)
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@kindex memset
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This is the standard library function @code{memset} that sets an area of
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memory to a known value. If you have one of the free versions of
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@code{libc.a}, @code{memset} can be found there; otherwise, you must
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either obtain it from your hardware manufacturer, or write your own.
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@end table
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If you do not use the GNU C compiler, you may need other standard
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library subroutines as well; this will vary from one stub to another,
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but in general the stubs are likely to use any of the common library
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subroutines which @code{gcc} generates as inline code.
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@node Debug Session
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@subsubsection Putting it all together
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@cindex remote serial debugging summary
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In summary, when your program is ready to debug, you must follow these
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steps.
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@enumerate
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@item
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Make sure you have the supporting low-level routines
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(@pxref{Bootstrapping}):
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@display
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@code{getDebugChar}, @code{putDebugChar},
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@code{flush_i_cache}, @code{memset}, @code{exceptionHandler}.
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@end display
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@item
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Insert these lines near the top of your program:
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@example
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set_debug_traps();
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breakpoint();
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@end example
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@item
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For the 680x0 stub only, you need to provide a variable called
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@code{exceptionHook}. Normally you just use
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@example
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void (*exceptionHook)() = 0;
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@end example
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but if before calling @code{set_debug_traps}, you set it to point to a
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function in your program, that function is called when
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@code{@value{GDBN}} continues after stopping on a trap (for example, bus
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error). The function indicated by @code{exceptionHook} is called with
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one parameter: an @code{int} which is the exception number.
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@item
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Compile and link together: your program, the @value{GDBN} debugging stub for
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your target architecture, and the supporting subroutines.
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@item
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Make sure you have a serial connection between your target machine and
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the @value{GDBN} host, and identify the serial port used for this on the host.
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@item
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@c The "remote" target now provides a `load' command, so we should
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@c document that. FIXME.
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Download your program to your target machine (or get it there by
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whatever means the manufacturer provides), and start it.
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@item
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To start remote debugging, run @value{GDBN} on the host machine, and specify
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as an executable file the program that is running in the remote machine.
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This tells @value{GDBN} how to find your program's symbols and the contents
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of its pure text.
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Then establish communication using the @code{target remote} command.
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Its argument is the name of the device you're using to control the
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target machine. For example:
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@example
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target remote /dev/ttyb
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@end example
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@noindent
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if the serial line is connected to the device named @file{/dev/ttyb}.
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@ignore
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@c this is from the old text, but it doesn't seem to make sense now that I've
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@c seen an example... pesch 4sep1992
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This will stop the remote machine if it is not already stopped.
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@end ignore
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@end enumerate
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Now you can use all the usual commands to examine and change data and to
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step and continue the remote program.
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To resume the remote program and stop debugging it, use the @code{detach}
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command.
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@cindex interrupting remote programs
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@cindex remote programs, interrupting
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Whenever @value{GDBN} is waiting for the remote program, if you type the
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interrupt character (often @key{C-C}), @value{GDBN} attempts to stop the
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program. This may or may not succeed, depending in part on the hardware
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and the serial drivers the remote system uses. If you type the
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interrupt character once again, @value{GDBN} displays this prompt:
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@example
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Interrupted while waiting for the program.
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Give up (and stop debugging it)? (y or n)
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@end example
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If you type @kbd{y}, @value{GDBN} abandons the remote debugging session.
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(If you decide you want to try again later, you can use @samp{target
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remote} again to connect once more.) If you type @kbd{n}, @value{GDBN}
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goes back to waiting.
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@node Protocol
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@subsubsection Outline of the communication protocol
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@cindex debugging stub, example
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@cindex remote stub, example
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@cindex stub example, remote debugging
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The stub files provided with @value{GDBN} implement the target side of the
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communication protocol, and the @value{GDBN} side is implemented in the
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@value{GDBN} source file @file{remote.c}. Normally, you can simply allow
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these subroutines to communicate, and ignore the details. (If you're
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implementing your own stub file, you can still ignore the details: start
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with one of the existing stub files. @file{sparc-stub.c} is the best
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organized, and therefore the easiest to read.)
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However, there may be occasions when you need to know something about
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the protocol---for example, if there is only one serial port to your
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target machine, you might want your program to do something special if
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it recognizes a packet meant for @value{GDBN}.
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@cindex protocol, @value{GDBN} remote serial
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@cindex serial protocol, @value{GDBN} remote
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@cindex remote serial protocol
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All @value{GDBN} commands and responses (other than acknowledgements, which
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are single characters) are sent as a packet which includes a
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checksum. A packet is introduced with the character @samp{$}, and ends
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with the character @samp{#} followed by a two-digit checksum:
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@example
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$@var{packet info}#@var{checksum}
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@end example
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@cindex checksum, for @value{GDBN} remote
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@noindent
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@var{checksum} is computed as the modulo 256 sum of the @var{packet
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info} characters.
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When either the host or the target machine receives a packet, the first
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response expected is an acknowledgement: a single character, either
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@samp{+} (to indicate the package was received correctly) or @samp{-}
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(to request retransmission).
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The host (@value{GDBN}) sends commands, and the target (the debugging stub
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incorporated in your program) sends data in response. The target also
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sends data when your program stops.
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Command packets are distinguished by their first character, which
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identifies the kind of command.
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These are the commands currently supported:
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@table @code
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@item g
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Requests the values of CPU registers.
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@item G
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Sets the values of CPU registers.
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@item m@var{addr},@var{count}
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Read @var{count} bytes at location @var{addr}.
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@item M@var{addr},@var{count}:@dots{}
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Write @var{count} bytes at location @var{addr}.
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@item c
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@itemx c@var{addr}
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Resume execution at the current address (or at @var{addr} if supplied).
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@item s
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@itemx s@var{addr}
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Step the target program for one instruction, from either the current
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program counter or from @var{addr} if supplied.
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@item k
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Kill the target program.
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@item ?
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Report the most recent signal. To allow you to take advantage of the
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@value{GDBN} signal handling commands, one of the functions of the debugging
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stub is to report CPU traps as the corresponding POSIX signal values.
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@end table
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@kindex set remotedebug
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@kindex show remotedebug
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@cindex packets, reporting on stdout
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@cindex serial connections, debugging
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If you have trouble with the serial connection, you can use the command
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@code{set remotedebug}. This makes @value{GDBN} report on all packets sent
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back and forth across the serial line to the remote machine. The
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packet-debugging information is printed on the @value{GDBN} standard output
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stream. @code{set remotedebug off} turns it off, and @code{show
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remotedebug} will show you its current state.
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@end ifset
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@ifset I960
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@node i960-Nindy Remote
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@subsection @value{GDBN} with a remote i960 (Nindy)
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@cindex Nindy
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@cindex i960
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@dfn{Nindy} is a ROM Monitor program for Intel 960 target systems. When
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@value{GDBN} is configured to control a remote Intel 960 using Nindy, you can
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tell @value{GDBN} how to connect to the 960 in several ways:
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@itemize @bullet
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@item
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Through command line options specifying serial port, version of the
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Nindy protocol, and communications speed;
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@item
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By responding to a prompt on startup;
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@item
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By using the @code{target} command at any point during your @value{GDBN}
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session. @xref{Target Commands, ,Commands for managing targets}.
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@end itemize
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@menu
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* Nindy Startup:: Startup with Nindy
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* Nindy Options:: Options for Nindy
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* Nindy Reset:: Nindy reset command
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@end menu
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@node Nindy Startup
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@subsubsection Startup with Nindy
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If you simply start @code{@value{GDBP}} without using any command-line
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options, you are prompted for what serial port to use, @emph{before} you
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reach the ordinary @value{GDBN} prompt:
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@example
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Attach /dev/ttyNN -- specify NN, or "quit" to quit:
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@end example
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@noindent
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Respond to the prompt with whatever suffix (after @samp{/dev/tty})
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identifies the serial port you want to use. You can, if you choose,
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simply start up with no Nindy connection by responding to the prompt
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with an empty line. If you do this and later wish to attach to Nindy,
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use @code{target} (@pxref{Target Commands, ,Commands for managing targets}).
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@node Nindy Options
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@subsubsection Options for Nindy
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These are the startup options for beginning your @value{GDBN} session with a
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Nindy-960 board attached:
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@table @code
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@item -r @var{port}
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Specify the serial port name of a serial interface to be used to connect
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to the target system. This option is only available when @value{GDBN} is
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configured for the Intel 960 target architecture. You may specify
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@var{port} as any of: a full pathname (e.g. @samp{-r /dev/ttya}), a
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device name in @file{/dev} (e.g. @samp{-r ttya}), or simply the unique
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suffix for a specific @code{tty} (e.g. @samp{-r a}).
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@item -O
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(An uppercase letter ``O'', not a zero.) Specify that @value{GDBN} should use
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the ``old'' Nindy monitor protocol to connect to the target system.
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This option is only available when @value{GDBN} is configured for the Intel 960
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target architecture.
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@quotation
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@emph{Warning:} if you specify @samp{-O}, but are actually trying to
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connect to a target system that expects the newer protocol, the connection
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fails, appearing to be a speed mismatch. @value{GDBN} repeatedly
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attempts to reconnect at several different line speeds. You can abort
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this process with an interrupt.
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@end quotation
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@item -brk
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Specify that @value{GDBN} should first send a @code{BREAK} signal to the target
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system, in an attempt to reset it, before connecting to a Nindy target.
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@quotation
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@emph{Warning:} Many target systems do not have the hardware that this
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requires; it only works with a few boards.
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@end quotation
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@end table
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|
|
The standard @samp{-b} option controls the line speed used on the serial
|
|
port.
|
|
|
|
@c @group
|
|
@node Nindy Reset
|
|
@subsubsection Nindy reset command
|
|
|
|
@table @code
|
|
@item reset
|
|
@kindex reset
|
|
For a Nindy target, this command sends a ``break'' to the remote target
|
|
system; this is only useful if the target has been equipped with a
|
|
circuit to perform a hard reset (or some other interesting action) when
|
|
a break is detected.
|
|
@end table
|
|
@c @end group
|
|
@end ifset
|
|
|
|
@ifset AMD29K
|
|
@node UDI29K Remote
|
|
@subsection @value{GDBN} and the UDI protocol for AMD29K
|
|
|
|
@cindex UDI
|
|
@cindex AMD29K via UDI
|
|
@value{GDBN} supports AMD's UDI (``Universal Debugger Interface'')
|
|
protocol for debugging the a29k processor family. To use this
|
|
configuration with AMD targets running the MiniMON monitor, you need the
|
|
program @code{MONTIP}, available from AMD at no charge. You can also
|
|
use @value{GDBN} with the UDI conformant a29k simulator program
|
|
@code{ISSTIP}, also available from AMD.
|
|
|
|
@table @code
|
|
@item target udi @var{keyword}
|
|
@kindex udi
|
|
Select the UDI interface to a remote a29k board or simulator, where
|
|
@var{keyword} is an entry in the AMD configuration file @file{udi_soc}.
|
|
This file contains keyword entries which specify parameters used to
|
|
connect to a29k targets. If the @file{udi_soc} file is not in your
|
|
working directory, you must set the environment variable @samp{UDICONF}
|
|
to its pathname.
|
|
@end table
|
|
|
|
@node EB29K Remote
|
|
@subsection @value{GDBN} and the EBMON protocol for AMD29K
|
|
|
|
@cindex EB29K board
|
|
@cindex running 29K programs
|
|
|
|
AMD distributes a 29K development board meant to fit in a PC, together
|
|
with a DOS-hosted monitor program called @code{EBMON}. As a shorthand
|
|
term, this development system is called the ``EB29K''. To use
|
|
@value{GDBN} from a Unix system to run programs on the EB29K board, you
|
|
must first connect a serial cable between the PC (which hosts the EB29K
|
|
board) and a serial port on the Unix system. In the following, we
|
|
assume you've hooked the cable between the PC's @file{COM1} port and
|
|
@file{/dev/ttya} on the Unix system.
|
|
|
|
@menu
|
|
* Comms (EB29K):: Communications setup
|
|
* gdb-EB29K:: EB29K cross-debugging
|
|
* Remote Log:: Remote log
|
|
@end menu
|
|
|
|
@node Comms (EB29K)
|
|
@subsubsection Communications setup
|
|
|
|
The next step is to set up the PC's port, by doing something like this
|
|
in DOS on the PC:
|
|
|
|
@example
|
|
C:\> MODE com1:9600,n,8,1,none
|
|
@end example
|
|
|
|
@noindent
|
|
This example---run on an MS DOS 4.0 system---sets the PC port to 9600
|
|
bps, no parity, eight data bits, one stop bit, and no ``retry'' action;
|
|
you must match the communications parameters when establishing the Unix
|
|
end of the connection as well.
|
|
@c FIXME: Who knows what this "no retry action" crud from the DOS manual may
|
|
@c mean? It's optional; leave it out? ---pesch@cygnus.com, 25feb91
|
|
|
|
To give control of the PC to the Unix side of the serial line, type
|
|
the following at the DOS console:
|
|
|
|
@example
|
|
C:\> CTTY com1
|
|
@end example
|
|
|
|
@noindent
|
|
(Later, if you wish to return control to the DOS console, you can use
|
|
the command @code{CTTY con}---but you must send it over the device that
|
|
had control, in our example over the @file{COM1} serial line).
|
|
|
|
From the Unix host, use a communications program such as @code{tip} or
|
|
@code{cu} to communicate with the PC; for example,
|
|
|
|
@example
|
|
cu -s 9600 -l /dev/ttya
|
|
@end example
|
|
|
|
@noindent
|
|
The @code{cu} options shown specify, respectively, the linespeed and the
|
|
serial port to use. If you use @code{tip} instead, your command line
|
|
may look something like the following:
|
|
|
|
@example
|
|
tip -9600 /dev/ttya
|
|
@end example
|
|
|
|
@noindent
|
|
Your system may require a different name where we show
|
|
@file{/dev/ttya} as the argument to @code{tip}. The communications
|
|
parameters, including which port to use, are associated with the
|
|
@code{tip} argument in the ``remote'' descriptions file---normally the
|
|
system table @file{/etc/remote}.
|
|
@c FIXME: What if anything needs doing to match the "n,8,1,none" part of
|
|
@c the DOS side's comms setup? cu can support -o (odd
|
|
@c parity), -e (even parity)---apparently no settings for no parity or
|
|
@c for character size. Taken from stty maybe...? John points out tip
|
|
@c can set these as internal variables, eg ~s parity=none; man stty
|
|
@c suggests that it *might* work to stty these options with stdin or
|
|
@c stdout redirected... ---pesch@cygnus.com, 25feb91
|
|
|
|
@kindex EBMON
|
|
Using the @code{tip} or @code{cu} connection, change the DOS working
|
|
directory to the directory containing a copy of your 29K program, then
|
|
start the PC program @code{EBMON} (an EB29K control program supplied
|
|
with your board by AMD). You should see an initial display from
|
|
@code{EBMON} similar to the one that follows, ending with the
|
|
@code{EBMON} prompt @samp{#}---
|
|
|
|
@example
|
|
C:\> G:
|
|
|
|
G:\> CD \usr\joe\work29k
|
|
|
|
G:\USR\JOE\WORK29K> EBMON
|
|
Am29000 PC Coprocessor Board Monitor, version 3.0-18
|
|
Copyright 1990 Advanced Micro Devices, Inc.
|
|
Written by Gibbons and Associates, Inc.
|
|
|
|
Enter '?' or 'H' for help
|
|
|
|
PC Coprocessor Type = EB29K
|
|
I/O Base = 0x208
|
|
Memory Base = 0xd0000
|
|
|
|
Data Memory Size = 2048KB
|
|
Available I-RAM Range = 0x8000 to 0x1fffff
|
|
Available D-RAM Range = 0x80002000 to 0x801fffff
|
|
|
|
PageSize = 0x400
|
|
Register Stack Size = 0x800
|
|
Memory Stack Size = 0x1800
|
|
|
|
CPU PRL = 0x3
|
|
Am29027 Available = No
|
|
Byte Write Available = Yes
|
|
|
|
# ~.
|
|
@end example
|
|
|
|
Then exit the @code{cu} or @code{tip} program (done in the example by
|
|
typing @code{~.} at the @code{EBMON} prompt). @code{EBMON} will keep
|
|
running, ready for @value{GDBN} to take over.
|
|
|
|
For this example, we've assumed what is probably the most convenient
|
|
way to make sure the same 29K program is on both the PC and the Unix
|
|
system: a PC/NFS connection that establishes ``drive @code{G:}'' on the
|
|
PC as a file system on the Unix host. If you do not have PC/NFS or
|
|
something similar connecting the two systems, you must arrange some
|
|
other way---perhaps floppy-disk transfer---of getting the 29K program
|
|
from the Unix system to the PC; @value{GDBN} will @emph{not} download it over the
|
|
serial line.
|
|
|
|
@node gdb-EB29K
|
|
@subsubsection EB29K cross-debugging
|
|
|
|
Finally, @code{cd} to the directory containing an image of your 29K
|
|
program on the Unix system, and start @value{GDBN}---specifying as argument the
|
|
name of your 29K program:
|
|
|
|
@example
|
|
cd /usr/joe/work29k
|
|
@value{GDBP} myfoo
|
|
@end example
|
|
|
|
Now you can use the @code{target} command:
|
|
|
|
@example
|
|
target amd-eb /dev/ttya 9600 MYFOO
|
|
@c FIXME: test above 'target amd-eb' as spelled, with caps! caps are meant to
|
|
@c emphasize that this is the name as seen by DOS (since I think DOS is
|
|
@c single-minded about case of letters). ---pesch@cygnus.com, 25feb91
|
|
@end example
|
|
|
|
@noindent
|
|
In this example, we've assumed your program is in a file called
|
|
@file{myfoo}. Note that the filename given as the last argument to
|
|
@code{target amd-eb} should be the name of the program as it appears to DOS.
|
|
In our example this is simply @code{MYFOO}, but in general it can include
|
|
a DOS path, and depending on your transfer mechanism may not resemble
|
|
the name on the Unix side.
|
|
|
|
At this point, you can set any breakpoints you wish; when you are ready
|
|
to see your program run on the 29K board, use the @value{GDBN} command
|
|
@code{run}.
|
|
|
|
To stop debugging the remote program, use the @value{GDBN} @code{detach}
|
|
command.
|
|
|
|
To return control of the PC to its console, use @code{tip} or @code{cu}
|
|
once again, after your @value{GDBN} session has concluded, to attach to
|
|
@code{EBMON}. You can then type the command @code{q} to shut down
|
|
@code{EBMON}, returning control to the DOS command-line interpreter.
|
|
Type @code{CTTY con} to return command input to the main DOS console,
|
|
and type @kbd{~.} to leave @code{tip} or @code{cu}.
|
|
|
|
@node Remote Log
|
|
@subsubsection Remote log
|
|
@kindex eb.log
|
|
@cindex log file for EB29K
|
|
|
|
The @code{target amd-eb} command creates a file @file{eb.log} in the
|
|
current working directory, to help debug problems with the connection.
|
|
@file{eb.log} records all the output from @code{EBMON}, including echoes
|
|
of the commands sent to it. Running @samp{tail -f} on this file in
|
|
another window often helps to understand trouble with @code{EBMON}, or
|
|
unexpected events on the PC side of the connection.
|
|
|
|
@end ifset
|
|
|
|
@ifset ST2000
|
|
@node ST2000 Remote
|
|
@subsection @value{GDBN} with a Tandem ST2000
|
|
|
|
To connect your ST2000 to the host system, see the manufacturer's
|
|
manual. Once the ST2000 is physically attached, you can run
|
|
|
|
@example
|
|
target st2000 @var{dev} @var{speed}
|
|
@end example
|
|
|
|
@noindent
|
|
to establish it as your debugging environment.
|
|
|
|
The @code{load} and @code{attach} commands are @emph{not} defined for
|
|
this target; you must load your program into the ST2000 as you normally
|
|
would for standalone operation. @value{GDBN} will read debugging information
|
|
(such as symbols) from a separate, debugging version of the program
|
|
available on your host computer.
|
|
@c FIXME!! This is terribly vague; what little content is here is
|
|
@c basically hearsay.
|
|
|
|
@cindex ST2000 auxiliary commands
|
|
These auxiliary @value{GDBN} commands are available to help you with the ST2000
|
|
environment:
|
|
|
|
@table @code
|
|
@item st2000 @var{command}
|
|
@kindex st2000 @var{cmd}
|
|
@cindex STDBUG commands (ST2000)
|
|
@cindex commands to STDBUG (ST2000)
|
|
Send a @var{command} to the STDBUG monitor. See the manufacturer's
|
|
manual for available commands.
|
|
|
|
@item connect
|
|
@cindex connect (to STDBUG)
|
|
Connect the controlling terminal to the STDBUG command monitor. When
|
|
you are done interacting with STDBUG, typing either of two character
|
|
sequences will get you back to the @value{GDBN} command prompt:
|
|
@kbd{@key{RET}~.} (Return, followed by tilde and period) or
|
|
@kbd{@key{RET}~@key{C-d}} (Return, followed by tilde and control-D).
|
|
@end table
|
|
@end ifset
|
|
|
|
@ifset VXWORKS
|
|
@node VxWorks Remote
|
|
@subsection @value{GDBN} and VxWorks
|
|
@cindex VxWorks
|
|
|
|
@value{GDBN} enables developers to spawn and debug tasks running on networked
|
|
VxWorks targets from a Unix host. Already-running tasks spawned from
|
|
the VxWorks shell can also be debugged. @value{GDBN} uses code that runs on
|
|
both the UNIX host and on the VxWorks target. The program
|
|
@code{gdb} is installed and executed on the UNIX host. (It may be
|
|
installed with the name @code{vxgdb}, to distinguish it from a
|
|
@value{GDBN} for debugging programs on the host itself.)
|
|
|
|
The following information on connecting to VxWorks was current when
|
|
this manual was produced; newer releases of VxWorks may use revised
|
|
procedures.
|
|
|
|
The remote debugging interface (RDB) routines are installed and executed
|
|
on the VxWorks target. These routines are included in the VxWorks library
|
|
@file{rdb.a} and are incorporated into the system image when source-level
|
|
debugging is enabled in the VxWorks configuration.
|
|
|
|
@kindex INCLUDE_RDB
|
|
If you wish, you can define @code{INCLUDE_RDB} in the VxWorks
|
|
configuration file @file{configAll.h} to include the RDB interface
|
|
routines and spawn the source debugging task @code{tRdbTask} when
|
|
VxWorks is booted. For more information on configuring and remaking
|
|
VxWorks, see the manufacturer's manual.
|
|
@c VxWorks, see the @cite{VxWorks Programmer's Guide}.
|
|
|
|
Once you have included the RDB interface in your VxWorks system image
|
|
and set your Unix execution search path to find @value{GDBN}, you are ready
|
|
to run @value{GDBN}. From your UNIX host, run @code{gdb} (or
|
|
@code{vxgdb}, depending on your installation).
|
|
|
|
@value{GDBN} comes up showing the prompt:
|
|
|
|
@example
|
|
(vxgdb)
|
|
@end example
|
|
|
|
@menu
|
|
* VxWorks Connection:: Connecting to VxWorks
|
|
* VxWorks Download:: VxWorks download
|
|
* VxWorks Attach:: Running tasks
|
|
@end menu
|
|
|
|
@node VxWorks Connection
|
|
@subsubsection Connecting to VxWorks
|
|
|
|
The @value{GDBN} command @code{target} lets you connect to a VxWorks target on the
|
|
network. To connect to a target whose host name is ``@code{tt}'', type:
|
|
|
|
@example
|
|
(vxgdb) target vxworks tt
|
|
@end example
|
|
|
|
@value{GDBN} displays messages like these:
|
|
|
|
@smallexample
|
|
Attaching remote machine across net...
|
|
Connected to tt.
|
|
@end smallexample
|
|
|
|
@value{GDBN} then attempts to read the symbol tables of any object modules
|
|
loaded into the VxWorks target since it was last booted. @value{GDBN} locates
|
|
these files by searching the directories listed in the command search
|
|
path (@pxref{Environment, ,Your program's environment}); if it fails
|
|
to find an object file, it displays a message such as:
|
|
|
|
@example
|
|
prog.o: No such file or directory.
|
|
@end example
|
|
|
|
When this happens, add the appropriate directory to the search path with
|
|
the @value{GDBN} command @code{path}, and execute the @code{target}
|
|
command again.
|
|
|
|
@node VxWorks Download
|
|
@subsubsection VxWorks download
|
|
|
|
@cindex download to VxWorks
|
|
If you have connected to the VxWorks target and you want to debug an
|
|
object that has not yet been loaded, you can use the @value{GDBN}
|
|
@code{load} command to download a file from UNIX to VxWorks
|
|
incrementally. The object file given as an argument to the @code{load}
|
|
command is actually opened twice: first by the VxWorks target in order
|
|
to download the code, then by @value{GDBN} in order to read the symbol
|
|
table. This can lead to problems if the current working directories on
|
|
the two systems differ. If both systems have NFS mounted the same
|
|
filesystems, you can avoid these problems by using absolute paths.
|
|
Otherwise, it is simplest to set the working directory on both systems
|
|
to the directory in which the object file resides, and then to reference
|
|
the file by its name, without any path. For instance, a program
|
|
@file{prog.o} may reside in @file{@var{vxpath}/vw/demo/rdb} in VxWorks
|
|
and in @file{@var{hostpath}/vw/demo/rdb} on the host. To load this
|
|
program, type this on VxWorks:
|
|
|
|
@example
|
|
-> cd "@var{vxpath}/vw/demo/rdb"
|
|
@end example
|
|
|
|
Then, in @value{GDBN}, type:
|
|
|
|
@example
|
|
(vxgdb) cd @var{hostpath}/vw/demo/rdb
|
|
(vxgdb) load prog.o
|
|
@end example
|
|
|
|
@value{GDBN} displays a response similar to this:
|
|
|
|
@smallexample
|
|
Reading symbol data from wherever/vw/demo/rdb/prog.o... done.
|
|
@end smallexample
|
|
|
|
You can also use the @code{load} command to reload an object module
|
|
after editing and recompiling the corresponding source file. Note that
|
|
this will cause @value{GDBN} to delete all currently-defined breakpoints,
|
|
auto-displays, and convenience variables, and to clear the value
|
|
history. (This is necessary in order to preserve the integrity of
|
|
debugger data structures that reference the target system's symbol
|
|
table.)
|
|
|
|
@node VxWorks Attach
|
|
@subsubsection Running tasks
|
|
|
|
@cindex running VxWorks tasks
|
|
You can also attach to an existing task using the @code{attach} command as
|
|
follows:
|
|
|
|
@example
|
|
(vxgdb) attach @var{task}
|
|
@end example
|
|
|
|
@noindent
|
|
where @var{task} is the VxWorks hexadecimal task ID. The task can be running
|
|
or suspended when you attach to it. If running, it will be suspended at
|
|
the time of attachment.
|
|
@end ifset
|
|
|
|
@ifset H8
|
|
@node Hitachi Remote
|
|
@subsection @value{GDBN} and Hitachi Microprocessors
|
|
@value{GDBN} needs to know these things to talk to your
|
|
Hitachi SH, H8/300, or H8/500:
|
|
|
|
@enumerate
|
|
@item
|
|
that you want to use @samp{target hms}, the remote debugging interface
|
|
for Hitachi microprocessors (this is the default when GDB is configured
|
|
specifically for the Hitachi SH, H8/300, or H8/500);
|
|
|
|
@item
|
|
what serial device connects your host to your Hitachi board (the first
|
|
serial device available on your host is the default);
|
|
|
|
@ignore
|
|
@c this is only for Unix hosts, not currently of interest.
|
|
@item
|
|
what speed to use over the serial device.
|
|
@end ignore
|
|
@end enumerate
|
|
|
|
@ifclear H8EXCLUSIVE
|
|
@c only for Unix hosts
|
|
@kindex device
|
|
@cindex serial device, Hitachi micros
|
|
Use the special @code{@value{GDBP}} command @samp{device @var{port}} if you
|
|
need to explicitly set the serial device. The default @var{port} is the
|
|
first available port on your host. This is only necessary on Unix
|
|
hosts, where it is typically something like @file{/dev/ttya}.
|
|
|
|
@kindex speed
|
|
@cindex serial line speed, Hitachi micros
|
|
@code{@value{GDBP}} has another special command to set the communications
|
|
speed: @samp{speed @var{bps}}. This command also is only used from Unix
|
|
hosts; on DOS hosts, set the line speed as usual from outside GDB with
|
|
the DOS @kbd{mode} command (for instance, @w{@samp{mode
|
|
com2:9600,n,8,1,p}} for a 9600 bps connection).
|
|
|
|
The @samp{device} and @samp{speed} commands are available only when you
|
|
use a Unix host to debug your Hitachi microprocessor programs. If you
|
|
use a DOS host,
|
|
@end ifclear
|
|
@value{GDBN} depends on an auxiliary terminate-and-stay-resident program
|
|
called @code{asynctsr} to communicate with the development board
|
|
through a PC serial port. You must also use the DOS @code{mode} command
|
|
to set up the serial port on the DOS side.
|
|
|
|
@ifset DOSHOST
|
|
The following sample session illustrates the steps needed to start a
|
|
program under @value{GDBN} control on an H8/300. The example uses a
|
|
sample H8/300 program called @file{t.x}. The procedure is the same for
|
|
the Hitachi SH and the H8/500.
|
|
|
|
First hook up your development board. In this example, we use a
|
|
board attached to serial port @code{COM2}; if you use a different serial
|
|
port, substitute its name in the argument of the @code{mode} command.
|
|
When you call @code{asynctsr}, the auxiliary comms program used by the
|
|
degugger, you give it just the numeric part of the serial port's name;
|
|
for example, @samp{asyncstr 2} below runs @code{asyncstr} on
|
|
@code{COM2}.
|
|
|
|
@example
|
|
(eg-C:\H8300\TEST) mode com2:9600,n,8,1,p
|
|
|
|
Resident portion of MODE loaded
|
|
|
|
COM2: 9600, n, 8, 1, p
|
|
|
|
(eg-C:\H8300\TEST) asynctsr 2
|
|
@end example
|
|
|
|
@quotation
|
|
@emph{Warning:} We have noticed a bug in PC-NFS that conflicts with
|
|
@code{asynctsr}. If you also run PC-NFS on your DOS host, you may need to
|
|
disable it, or even boot without it, to use @code{asynctsr} to control
|
|
your development board.
|
|
@end quotation
|
|
|
|
@kindex target hms
|
|
Now that serial communications are set up, and the development board is
|
|
connected, you can start up @value{GDBN}. Call @code{@value{GDBP}} with
|
|
the name of your program as the argument. @code{@value{GDBP}} prompts
|
|
you, as usual, with the prompt @samp{(@value{GDBP})}. Use two special
|
|
commands to begin your debugging session: @samp{target hms} to specify
|
|
cross-debugging to the Hitachi board, and the @code{load} command to
|
|
download your program to the board. @code{load} displays the names of
|
|
the program's sections, and a @samp{*} for each 2K of data downloaded.
|
|
(If you want to refresh @value{GDBN} data on symbols or on the
|
|
executable file without downloading, use the @value{GDBN} commands
|
|
@code{file} or @code{symbol-file}. These commands, and @code{load}
|
|
itself, are described in @ref{Files,,Commands to specify files}.)
|
|
|
|
@smallexample
|
|
(eg-C:\H8300\TEST) @value{GDBP} t.x
|
|
GDB is free software and you are welcome to distribute copies
|
|
of it under certain conditions; type "show copying" to see
|
|
the conditions.
|
|
There is absolutely no warranty for GDB; type "show warranty"
|
|
for details.
|
|
GDB @value{GDBVN}, Copyright 1992 Free Software Foundation, Inc...
|
|
(gdb) target hms
|
|
Connected to remote H8/300 HMS system.
|
|
(gdb) load t.x
|
|
.text : 0x8000 .. 0xabde ***********
|
|
.data : 0xabde .. 0xad30 *
|
|
.stack : 0xf000 .. 0xf014 *
|
|
@end smallexample
|
|
|
|
At this point, you're ready to run or debug your program. From here on,
|
|
you can use all the usual @value{GDBN} commands. The @code{break} command
|
|
sets breakpoints; the @code{run} command starts your program;
|
|
@code{print} or @code{x} display data; the @code{continue} command
|
|
resumes execution after stopping at a breakpoint. You can use the
|
|
@code{help} command at any time to find out more about @value{GDBN} commands.
|
|
|
|
Remember, however, that @emph{operating system} facilities aren't
|
|
available on your development board; for example, if your program hangs,
|
|
you can't send an interrupt---but you can press the @sc{reset} switch!
|
|
|
|
Use the @sc{reset} button on the development board
|
|
@itemize @bullet
|
|
@item
|
|
to interrupt your program (don't use @kbd{ctl-C} on the DOS host---it has
|
|
no way to pass an interrupt signal to the development board); and
|
|
|
|
@item
|
|
to return to the @value{GDBN} command prompt after your program finishes
|
|
normally. The communications protocol provides no other way for @value{GDBN}
|
|
to detect program completion.
|
|
@end itemize
|
|
|
|
In either case, @value{GDBN} will see the effect of a @sc{reset} on the
|
|
development board as a ``normal exit'' of your program.
|
|
@end ifset
|
|
@end ifset
|
|
|
|
@ifset MIPS
|
|
@node MIPS Remote
|
|
@subsection @value{GDBN} and remote MIPS boards
|
|
|
|
@cindex MIPS boards
|
|
@value{GDBN} can use the MIPS remote debugging protocol to talk to a
|
|
MIPS board attached to a serial line. This is available when
|
|
you configure @value{GDBN} with @samp{--target=mips-idt-ecoff}.
|
|
|
|
@kindex target mips @var{port}
|
|
To run a program on the board, start up @code{@value{GDBP}} with the
|
|
name of your program as the argument. To connect to the board, use the
|
|
command @samp{target mips @var{port}}, where @var{port} is the name of
|
|
the serial port connected to the board. If the program has not already
|
|
been downloaded to the board, you may use the @code{load} command to
|
|
download it. You can then use all the usual @value{GDBN} commands.
|
|
|
|
@cindex @code{remotedebug}, MIPS protocol
|
|
@c FIXME! For this to be useful, you must know something about the MIPS
|
|
@c FIXME...protocol. Where is it described?
|
|
You can see some debugging information about communications with the board
|
|
by setting the @code{remotedebug} variable. If you set it to 1 using
|
|
@samp{set remotedebug 1} every packet will be displayed. If you set it
|
|
to 2 every character will be displayed. You can check the current value
|
|
at any time with the command @samp{show remotedebug}.
|
|
|
|
@kindex set mipsfpu off
|
|
@cindex MIPS remote floating point
|
|
@cindex floating point, MIPS remote
|
|
If your target board does not support the MIPS floating point
|
|
coprocessor, you should use the command @samp{set mipsfpu off} (you may
|
|
wish to put this in your @value{GDBINIT} file). This will tell
|
|
@value{GDBN} how to find the return value of functions which return
|
|
floating point values, and tell it to call functions on the board
|
|
without saving the floating point registers.
|
|
@end ifset
|
|
|
|
@ifset SIMS
|
|
@node Simulator
|
|
@subsection Simulated CPU target
|
|
|
|
@ifset GENERIC
|
|
@cindex simulator
|
|
@cindex simulator, Z8000
|
|
@cindex Z8000 simulator
|
|
@cindex simulator, H8/300 or H8/500
|
|
@cindex H8/300 or H8/500 simulator
|
|
@cindex simulator, Hitachi SH
|
|
@cindex Hitachi SH simulator
|
|
@cindex CPU simulator
|
|
For some configurations, @value{GDBN} includes a CPU simulator that you
|
|
can use instead of a hardware CPU to debug your programs. Currently,
|
|
a simulator is available when @value{GDBN} is configured to debug Zilog
|
|
Z8000 or Hitachi microprocessor targets.
|
|
@end ifset
|
|
|
|
@ifclear GENERIC
|
|
@ifset H8
|
|
@cindex simulator, H8/300 or H8/500
|
|
@cindex Hitachi H8/300 or H8/500 simulator
|
|
@cindex simulator, Hitachi SH
|
|
@cindex Hitachi SH simulator
|
|
When configured for debugging Hitachi microprocessor targets,
|
|
@value{GDBN} includes a CPU simulator for the target chip (a Hitachi SH,
|
|
H8/300, or H8/500).
|
|
@end ifset
|
|
|
|
@ifset Z8K
|
|
@cindex simulator, Z8000
|
|
@cindex Zilog Z8000 simulator
|
|
When configured for debugging Zilog Z8000 targets, @value{GDBN} includes
|
|
a Z8000 simulator.
|
|
@end ifset
|
|
@end ifclear
|
|
|
|
@ifset Z8K
|
|
For the Z8000 family, @samp{target sim} simulates either the Z8002 (the
|
|
unsegmented variant of the Z8000 architecture) or the Z8001 (the
|
|
segmented variant). The simulator recognizes which architecture is
|
|
appropriate by inspecting the object code.
|
|
@end ifset
|
|
|
|
@table @code
|
|
@item target sim
|
|
@kindex sim
|
|
@kindex target sim
|
|
Debug programs on a simulated CPU
|
|
@ifset GENERIC
|
|
(which CPU depends on the @value{GDBN} configuration)
|
|
@end ifset
|
|
@end table
|
|
|
|
@noindent
|
|
After specifying this target, you can debug programs for the simulated
|
|
CPU in the same style as programs for your host computer; use the
|
|
@code{file} command to load a new program image, the @code{run} command
|
|
to run your program, and so on.
|
|
|
|
As well as making available all the usual machine registers (see
|
|
@code{info reg}), this debugging target provides three additional items
|
|
of information as specially named registers:
|
|
|
|
@table @code
|
|
@item cycles
|
|
Counts clock-ticks in the simulator.
|
|
|
|
@item insts
|
|
Counts instructions run in the simulator.
|
|
|
|
@item time
|
|
Execution time in 60ths of a second.
|
|
@end table
|
|
|
|
You can refer to these values in @value{GDBN} expressions with the usual
|
|
conventions; for example, @w{@samp{b fputc if $cycles>5000}} sets a
|
|
conditional breakpoint that will suspend only after at least 5000
|
|
simulated clock ticks.
|
|
@end ifset
|